<template>
  <div>
    <table border="1" width="700" style="border-collapse: collapse">
      <caption>
        购物车
      </caption>
      <thead>
        <tr>
          <th>
            <input type="checkbox" v-model="isAll" @click="btn" />
            <span>全选</span>
          </th>
          <th>名称</th>
          <th>价格</th>
          <th>数量</th>
          <th>总价</th>
          <th>操作</th>
        </tr>
        <tr v-for="(item, index) in goodList" :key="index">
          <th>
            <input type="checkbox" v-model="item.checked" />
          </th>
          <th>{{ item.name }}</th>
          <th>{{ item.price }}</th>
          <th>
            <input type="button" value="-" @click="fn(index)" />
            {{ item.num }}
            <input type="button" value="+" @click="add(index)" />
          </th>
          <th>{{ item.price * item.num }}</th>
          <th><input type="button" value="删除" @click="del(index)" /></th>
        </tr>
      </thead>
      <tbody></tbody>
      <tfoot>
        <tr>
          <td>合计:</td>
          <td colspan="5">
            {{ allPrice }}
          </td>
        </tr>
      </tfoot>
    </table>
  </div>
</template>

<script>
import { set } from "vue";
export default {
  data() {
    return {
      goodList: [
        {
          name: "诸葛亮",
          price: 1000,
          num: 1,
          checked: false,
        },
        {
          name: "蔡文姬",
          price: 1500,
          num: 1,
          checked: false,
        },
        {
          name: "妲己",
          price: 2000,
          num: 1,
          checked: false,
        },
        {
          name: "鲁班",
          price: 2200,
          num: 1,
          checked: false,
        },
      ],
    };
  },
  methods: {
    btn() {
      this.goodList.forEach((item) => (item.checked = !item.checked));
    },
    fn(index) {
      this.goodList[index].num > 0 && this.goodList[index].num--;
    },
    add(index) {
      this.goodList[index].num++;
    },
    del(index) {
      this.goodList.splice(index, 1);
    },
  },
  computed: {
    isAll: {
      get() {
        return this.goodList.every((item) => item.checked);
      },
      set(val) {
        this.goodList.forEach((item) => (item.checked = val));
      },
    },
    allPrice() {
      return (this.goodList.filter((obj) => obj.checked === true) || []).reduce(
        (sum, obj) => (sum += obj.price * obj.num),
        0
      );
    },
  },
};
</script>

<style>
</style>